'Satanism: A Beginner's Guide to the Religious Worship of Satan and Demons Volume I: Philosophy'
I wouldn't really recommend it other than it has a good translation of the Yazidi holy text at the back. The author seems to think we will all be fighting for the Anti-Christ against the armies of Jesus during the battle of Armageddon so it's like a reverse Christianity or reverse Jehovah's Witness.
That says nothing about whether the fetus has "the Satanic gene", right?
According to the author Satanists have their DNA divinely enhanced by the Devil and this would be passed onto an unborn fetus. I don't know whether you get this enhancement after deciding to worship Satan or whether he singles individuals out to become a superior form of human. He's not clear on exactly that's supposed to work.